Vaginal seeding is the practice of collecting a mother’s vaginal bacteria with gauze and wiping it over the newborn’s mouth, eyes, face, and skin. Health care professionals around the world have increasingly taken up the practice, which is believed to provide the baby with a host of beneficial germs. But an article published in the British Medical Journal now suggests medical professionals hold off on using the technique until more research is done on its benefits and risks.

The bacteria that babies are exposed to during their first few moments of life can affect their long-term health. Babies born via C-section, however, miss out on exposure to the bacteria in the vagina. According to Discover magazine, this causes them to develop different, less diverse gut bacteria. With vaginal seeding, doctors are able to spread the good bacteria around and inside the baby.

It’s believed vaginal seeding helps to coax the bacterial colonization the babies missed, while also shielding them from harmful bacteria. If this is true, then it would confer long-term health benefits, specifically to the child’s digestive and immune systems. For example, research has shown children born via C-section are more likely to have digestive conditions like irritable bowel syndrome and allergies, which are an abnormal immune reaction.

While the BMJ authors don’t refute the benefits of vaginal bacteria to the newborn baby, they say it’s unclear if vaginal seeding actually does a sufficient job at recreating the natural process.

“At the moment, we're a long way from having the evidence base to recommend this practice. There is simply no evidence to suggest it has benefits. And it may carry potential risks,” said study author Dr. Aubrey Cunnington, from the Department of Medicine at Imperial College London, in a recent statement.

Some women, for example, carry STDs like gonorrhea and herpes. If transferred from mother to child from a swab, these pathogens could cause harm to newborns, including severe infection or death. With 32 percent of all deliveries in the United States done via C-section and 20 million new cases of STDs each year, the risk associated with vaginal seeding may outweigh the benefits.

“People have made a leap of logic that gut bacteria must be the link between caesarean section and risk of these diseases,” said Cunnington. “But we just don't know this for sure — or whether we can even influence this by transferring bacteria on a swab from mom to baby."

In the meantime, medical professionals can contribute to newborns’ better health by encouraging techniques that have already been proven to work, such as breastfeeding and limiting antibiotic use.

Source: Cunnington AJ. Sim K, Deierl A, et al. “Vaginal seeding” of infants born by caesarean section How should health professionals engage with this increasingly popular but unproved practice? BMJ . 2016